This invention relates to an apparatus for coupling a rotating control means to a stationary switch means. More particularly, it relates to a means for mechanically passing information to a switch through a rotating swivel for controlling a machine.
As the lumber business has become more and more mechanized, various machines have been introduced for efficiently sawing and loading lumber. One such machine is a hydraulic loader which is normally mounted on the back of a truck. The hydraulic loader picks up saw logs to be sawed into shorter sections, as well as stacks them onto a waiting truck or a stockpile. A source of hydraulic pressure to operate this loader is normally also mounted on the truck. The operator of the loader sits on a table which is mounted on top of a swivel. The grapples are also mounted on the table which is adapted to rotate freely, even through rotations greater than 360.degree. if desired. The operator on the table utilizes various hydraulic controls for controlling the grapple and other devices. High pressure hoses are utilized to transfer the hydraulic control signals as well as the hydraulic power to the devices to be operated. However, since the swivel is adapted to turn through angles even greater than 360.degree., it is impossible to run high pressure hoses directly to the operator's hydraulic valve switches and out to the grapple because these hoses would become twisted and eventually rupture. Therefore, manufacturers of these loaders utilize complex hydraulic oil portals through the swivel coupling whereby the oil under pressure from the source on the truck is fed to the swivel and coupled through these portals to other pressure hoses leading from the swivel through the operator's switches on the rotating table and then to the grapple. An example of this hose through swivel to hose coupling is shown in FIG. 2. Swivel 5 couples hoses 50 to hoses 51 through internal portals (not shown). One such hydraulic loader is the Prentice 150 hydraulic loader manufactured by the Hydraulic Materials Division of Omar Industries and distributed through various distributors, such as Farm Equipment Company of Asheville, N.C., assignee of the present invention.
If a logger wished to add any additional equipment to be controlled by the operator who sits in the rotating table, he could not easily do so using this type of loader because the number of portals are fixed in the swivel corresponding to the number of hydraulic cylinders to be driven on the loader.
One such piece of additional equipment that is quite often used by lumber operators is a power saw such as the Hydro-Saw Buck manufactured by Forest Equipment Manufacturing Company, a subsidiary of Farm Equipment Company of Asheville, N.C., assignee of the present invention. As shown in FIG. 1, this saw is normally positioned adjacent to the loader so that the operator may insert logs into the bed of the saw by the grapple. The Hydro-Saw Buck utilizes hydraulic oil pressure to operate the saw. As more and more logging businesses are converting from hand saws to the use of this hydraulically operated saw, it has become apparent that there is a need for the loader-operator sitting on the rotating table to be able to control this saw from the table by himself. Again it would be impractical to run hydraulic hoses through the opening for the swivel and up to the operator controls because the line would twist and probably sever after several turns of the table. It is, of course, possible to redesign the swivel mechanism itself to add another hydraulic portal, however, this would require retooling and also would require a substantial change in the existing loaders. It is, therefore, desirable to easily and inexpensively retrofit the current loaders so that the operator on a rotating table may control additional equipment from his normal working position.